Title

Author(s)

School Name

Grade Level

12th Grade

Presentation Topic

Biochemistry

Presentation Type

Mentored

Mentor

Mentor: Zsolt Ablonczy, Department of Ophthalmology, Medical University of South Carolina

Abstract

Neovascular, or wet, age-related macular degeneration (AMD) is spurred by the collapse of the retinal pigment epithelial (RPE) barrier system. This breakdown in barrier function is often attributed to oxidative stress. As wet AMD occurs, vascular endothelial growth factor (VEGF) spurs the development of new, leaky blood vessels which penetrate the RPE cell layer. The subsequent buildup of subretinal fluid is responsible for the loss of vision in patients with neovascular AMD. Pigment epithelial derived factor (PEDF) acts as a VEGF antagonist. The 44-mer PEDF peptide has been identified as being responsible for the neurotropic properties of PEDF while the 34-mer peptide has been seen to contain antiangiogenic properties. To assess the function of the 44-mer peptide in these processes, oxidative stress must be induced in ARPE-19 cell cultures via treatment with tert-butyl hydroperoxide. However, even in low concentrations, this agent may be lethal to injured cells in culture. To determine the concentration which would prompt oxidative stress without harming the cells, ARPE-19 monolayers were treated with varying tert-butyl concentrations. Barrier integrity was then assessed by measuring transepithelial resistance.

Start Date

End Date

Neovascular, or wet, age-related macular degeneration (AMD) is spurred by the collapse of the retinal pigment epithelial (RPE) barrier system. This breakdown in barrier function is often attributed to oxidative stress. As wet AMD occurs, vascular endothelial growth factor (VEGF) spurs the development of new, leaky blood vessels which penetrate the RPE cell layer. The subsequent buildup of subretinal fluid is responsible for the loss of vision in patients with neovascular AMD. Pigment epithelial derived factor (PEDF) acts as a VEGF antagonist. The 44-mer PEDF peptide has been identified as being responsible for the neurotropic properties of PEDF while the 34-mer peptide has been seen to contain antiangiogenic properties. To assess the function of the 44-mer peptide in these processes, oxidative stress must be induced in ARPE-19 cell cultures via treatment with tert-butyl hydroperoxide. However, even in low concentrations, this agent may be lethal to injured cells in culture. To determine the concentration which would prompt oxidative stress without harming the cells, ARPE-19 monolayers were treated with varying tert-butyl concentrations. Barrier integrity was then assessed by measuring transepithelial resistance.